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Handling big data has largely been a major bottleneck in traditional statistical models. Consequently, when accurate point prediction is the primary target, machine learning models are often preferred over their statistical counterparts for…

Methodology · Statistics 2021-04-02 Arindam Fadikar , Stefan M. Wild , Jonas Chaves-Montero

Whilst the underlying assumption of the Friedman-Lema\^itre-Robertson-Walker (FLRW) cosmological model is that matter is homogeneously distributed throughout the universe, gravitational influences over the life of the universe have resulted…

Cosmology and Nongalactic Astrophysics · Physics 2023-03-15 Sonia Akter Ema , Md Rasel Hossen , Krzysztof Bolejko , Geraint F. Lewis

We characterize galaxy correlations in the Sloan Digital Sky Survey by measuring several moments of galaxy counts in spheres. We firstly find that the average counts grows as a power-law function of the distance with an exponent D= 2.1+-…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 Francesco Sylos Labini

Super-sample covariance (SSC) is the dominant source of statistical error on large scale structure (LSS) observables for both current and future galaxy surveys. In this work, we concentrate on the SSC of cluster counts, also known as sample…

Cosmology and Nongalactic Astrophysics · Physics 2018-07-06 Fabien Lacasa , Marcos Lima , Michel Aguena

We present an investigation into the effects of survey systematics such as varying depth, point spread function (PSF) size, and extinction on the galaxy selection and correlation in photometric, multi-epoch, wide area surveys. We take the…

Cosmology and Nongalactic Astrophysics · Physics 2015-09-16 Christopher Brian Morrison , Hendrik Hildebrandt

I discuss the effects of measurement error on regression and density estimation. I review the statistical methods that have been developed to correct for measurement error that are most popular in astronomical data analysis, discussing…

Instrumentation and Methods for Astrophysics · Physics 2011-12-09 Brandon C. Kelly

The next generation of galaxy surveys will observe millions of galaxies over large volumes of the universe. These surveys are expensive both in time and cost, raising questions regarding the optimal investment of this time and money. In…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 P. Paykari , A. H. Jaffe

We present a method for removal of the contaminating effects of intrinsic galaxy alignments, in measurements of cosmic shear from multi-colour weak lensing surveys. The method down-weights pairs which are likely to be close in three…

Astrophysics · Physics 2007-05-23 Catherine Heymans , Alan Heavens

The systematic magnification of background sources by the weak gravitational-lensing effects of foreground matter, also called cosmic magnification, is becoming an efficient tool both for measuring cosmological parameters and for exploring…

Astrophysics · Physics 2015-06-24 Brice Menard , Takashi Hamana , Matthias Bartelmann , Naoki Yoshida

Weak lensing has become an increasingly important tool in cosmology and the use of galaxy shapes to measure cosmic shear has become routine. The weak-lensing distortion tensor contains two other effects in addition to the two components of…

Cosmology and Nongalactic Astrophysics · Physics 2018-09-19 Daniel B. Thomas , Lee Whittaker , Stefano Camera , Michael L. Brown

Future weak lensing surveys potentially hold the highest statistical power for constraining cosmological parameters compared to other cosmological probes. The statistical power of a weak lensing survey is determined by the sky coverage, the…

Cosmology and Nongalactic Astrophysics · Physics 2017-12-05 C. Chang , M. Jarvis , B. Jain , S. M. Kahn , D. Kirkby , A. Connolly , S. Krughoff , E. Peng , J. R. Peterson

It has been proposed that the cosmological constant $\Lambda$ might be measured from geometric effects on large-scale structure. A positive vacuum density leads to correlation-function contours which are squashed in the radial direction…

Astrophysics · Physics 2015-06-24 W. E. Ballinger , J. A. Peacock , A. F. Heavens

We describe an efficient algorithm for calculating the statistics of weak lensing by large-scale structure based on a tiled set of independent particle-mesh N-body simulations which telescope in resolution along the line of sight. This…

Astrophysics · Physics 2008-11-26 Martin White , Wayne Hu

The magnification of galaxies in modern galaxy surveys induces additional correlations in the cosmic shear, galaxy-galaxy lensing and clustering observables used in modern lensing "3x2pt" analyses, due to sample selection. In this paper, we…

Cosmology and Nongalactic Astrophysics · Physics 2022-07-06 Christopher A. J. Duncan , Joachim Harnois-Déraps , Lance Miller

Observational surveys of galaxies are not trivially related to single-epoch snapshots from computer simulations. Observationally, an increase in the distance along the line-of-sight corresponds to an earlier cosmic time at which the…

Astrophysics · Physics 2009-11-13 Joseph A. Muñoz , Abraham Loeb

Evolution of the statistical distribution of density field is investigated by means of a counts-in-cells method in a low-density cold-dark-matter simulated universe. Four theoretical distributions, i.e. the negative binomial distribution,…

Astrophysics · Physics 2015-06-24 Haruhiko Ueda , Jun'ichi Yokoyama

Statistical analyses of finite sample distributions usually assume that fluctuations are self-averaging, i.e. that they are statistically similar in different regions of the given sample volume. By using the scale-length method, we test…

Cosmology and Nongalactic Astrophysics · Physics 2010-11-02 Francesco Sylos Labini , Nikolay L. Vasilyev , Yurij V. Baryshev

We study the impact of lensing magnification on the observed three-dimensional galaxy clustering in redshift space. We used the RayGal suite of N-body simulations, from which we extracted samples of dark matter particles and haloes in the…

Cosmology and Nongalactic Astrophysics · Physics 2022-05-25 Michel-Andrès Breton , Sylvain de la Torre , Jade Piat

Current and future imaging surveys will measure cosmic shear with a statistical precision that demands a deeper understanding of potential systematic biases in galaxy shape measurements than has been achieved to date. We investigate the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-18 J. E. Meyers , P. R. Burchat

Studies of the distribution and evolution of galaxies are of fundamental importance to modern cosmology; these studies, however, are hampered by the complexity of the competing effects of spectral and density evolution. Constructing a…

Astrophysics · Physics 2009-10-31 R. J. Brunner , A. J. Connolly , A. S. Szalay